Method and apparatus for automatically positioning electronic dice within component packages

ABSTRACT

A method and apparatus of assembling and disassembling semiconductor dice to be tested from the components of a temporary test package. A computer-controlled vision system is employed to align the dice with the temporary test package bases, and an automated robot arm system is employed to retrieve and assemble the dice with the various package components. The invention has particular utility in the burn-in and other pre-packaging testing of die to establish known good dice (KGD).

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/228,809 filed Apr. 18, 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to computer-aided methods andsystems for manufacturing products in a high volume, automated,continuous process and, more particularly, to improved methods andapparatus for automated retrieval, alignment, placement and securementof singulated bare semiconductor dice within preformed packages fortesting and burn-in, followed by optional subsequent removal of the dicefrom the packages.

2. State of the Art

Integrated circuit devices are well-known in the prior art. Suchdevices, or so-called "dice," may include a large number of activesemiconductor components (such as diodes, transistors) in combinationwith (e.g., in one or more circuits with) various passive components(such as capacitors, resistors), all residing on a "chip" or die ofsilicon or, less typically, gallium arsenide. The combination ofcomponents results in a semiconductor or integrated circuit die whichperforms one or more specific functions, such as a microprocessor die ora memory die, as exemplified by ROM, PROM, EPROM, EEPROM, DRAM and SRAM.

Such dice are normally designed to be supported or carried in a packagehaving a plurality of externally-accessible pins or leads, to whichterminals such as bond pads on the die are electrically connected withinthe package to access other electronic components employed incombination with the die. A package provides mechanical support andprotection for the die, may serve as a heat sink, and is normally squareor rectangular in shape. The packages typically comprise a filledpolymer compound transfer molded about a die wire-bonded or otherwiseelectrically connected and physically supported by a lead framestructure, or a two-piece preformed ceramic package to which the die isphysically and electrically connected before the package lid is secured.Met packages are also used, although generally in small quantities andfor so-called "military spec" applications.

Packaging defective dice or unknown bad dice (UBD) which are packaged,tested and then scrapped after proven defective in post-packagingtesting is inefficient and costly. Accordingly, the bare dice are oftentested for continuity during the die fabrication process and beforepackaging. Such testing may be and has been accomplished by placing baredie in temporary packages having terminals aligned with the terminals(bond pads) of the die to provide electrical access to the devices onthe die and subjecting the die via the assembled package to extensivetesting, which includes burn-in and discrete testing. Exemplarystate-of-the-art fixtures and temporary packages for die testing aredisclosed in U.S. Pat. Nos. 5,367,253 and 5,519,332 (to some of theinventors named herein); 5,448,165; 5,475,317; 5,468,157; 5,468,158;5,483,174; 5,451,165; 5,479,105; 5,088,190; and 5,073,117. U.S. Pat.Nos. 5,367,253 and 5,519,332, assigned to the assignee of the presentapplication, are each hereby incorporated herein for al purposes by thisreference.

Discrete testing includes testing the die devices for speed and forerrors which may occur after fabrication and after burn-in. Burn-intesting is conducted at elevated potentials and for a prolonged periodof time, typically 24 hours, at varying and reduced and elevatedtemperatures such as -15° C. to 125° C. to accelerate failure mechanismssuch that die devices which have the potential to prematurely failduring normal operation can be identified and eliminated. Dice whichsurvive discrete testing and burn-in are termed "known good die," orKGD.

Failure of one die on a multi-chip module (MCM), including a so-calledsingle in-line memory module (SIMM), compromises performance of theentire module or, if identified after assembly but before shipment tothe customer, at the least initiates a relatively costly andtime-consuming rework process to replace the bad die if the entire MCMis not to be scrapped. Even if individual die yield is relatively high,the combination of such dice in an MCM nonetheless produces an abysmalmodule yield. For example, if a particular MCM design includes twenty(20) dice with an average "good die" yield rate of 97.3%, the overallyield rate would be predicted to be a dismal 57.3%, which is notcommercially viable. Moreover, subjecting the printed circuit or otherdie carrier of the MCM to burn-in may not be desirable as causingunnecessary stress on elements of the MCM other than the die. Therefore,employing KGD in an MCM is perceived as an optimum way to fabricatehigh-reliability multi-die products.

However, while desirable, testing bare, unpackaged dice requires asignificant amount of handling. The temporary package must not only becompatible with test and burn-in procedures, but must also physicallysecure and electrically access the die without damaging the die at thebond pads or elsewhere. Similarly, assembly of the die with the packageand disassembly after testing must be effected without die damage. Thesmall size of the die itself and minute pitch (spacing) of the bond padsof the die, as well as the fragile nature of the thin bond pads andprotective layer covering devices and circuit elements on the activesurface of the die, makes a somewhat complex task extremely delicate.Performing these operations at high speeds with requisite accuracy andrepeatability has proven beyond the capabilities of the state of theart.

Bond pads are discrete conductive areas on the active face of the diewhich are used for connecting the internal die circuitry to theconductors of the package. Accurate positioning of the die within thetemporary package is therefore critical since alignment of the die bondpads relative to the contacts of the temporary package electricalconductors must be effected in order to subject the die to testing.

Precising die packaging includes mechanically locating a component in aprecise position or placement. Various "precising" methods for thispurpose are known in the art. However, there have been several problemsassociated with such precising methods and systems. For example, it hasproven difficult to position the die bond pads in electrical contactwith temporary package electrical contacts in an accurate and consistentmanner so as to facilitate a repeatable, high volume, continuousassembly process of dice within temporary packages. Another disadvantageassociated with prior art equipment and processes is that the die isoften destroyed or damaged upon contact with the temporary package,lowering product yield and profit margins. Accurate, repeatablepositioning placement and securement of the die in the temporary packageis thus critical to providing acceptable KGD qualification on acommercial basis.

One attempt to overcome the problems associated with the prior art hasbeen to precise dice and packages by mechanical fixturing. However,assembly tolerances used in mechanical fixturing techniques are ofteninsufficiently fine to prevent improper alignment. Mechanical fixturingalso leads to damage of the die or temporary package. While suchtechniques have proven useful in improving the accuracy and reliabilityof the die placement, these techniques do not enable dice to beprecisely positioned within temporary packages in a manner that allowsproduction efficiencies capable of supporting large volume operations.

Other systems for alignment and, optionally, placement of various bareand packaged dice are also known in the art. See, for example, U.S. Pat.Nos. 4,526,646; 4,543,659; 4,736,437; 5,052,606; 5,059,559; 5,113,565;5,123,823; 5,145,099; 5,238,174; 5,288,698; 5,463,227; and 5,471,310 forvision-based systems. A commercially available vision-based alignerbonder for flip chip bonding, offered by Research Devices of Piscataway,N.J., has also been modified by the assignee of the present inventionfor manual alignment of bare dice with the electrical contacts of atemporary package employed in KGD qualification. It is believed thatcertain aspects of the commercial Research Devices system may bedisclosed in U.S. Pat. No. 4,899,921. A description of the modifiedResearch Devices system appears in the aforementioned U.S. Pat. No.5,519,332, assigned to the assignee of the present invention andincorporated herein for all purposes by this reference. A discussion ofvision systems' potential applications in the semiconductor industry andassociated problems appears in "A Vision of Vision in the Gigabit Era,"SEMICONDUCTOR INTERNATIONAL, June 1993, pp. 120-122, 124.

While the foregoing mechanical and visual alignment systems, withancillary mechanisms for die handling, have achieved some success intheir intended applications, to the inventors' knowledge there exists nofully-automated bare die and package assembly and disassembly systemcapable of accurate and repeatable operation at a speed making KGDqualification or characterization commercially viable for use as amatter of course in the die fabrication process.

Accordingly, there remains a long-felt need in the semiconductorindustry to provide for improved methods and apparatus for assemblingdice to be tested with temporary packages (and subsequentlydisassembling the dice from the packages) in a high volume,cost-efficient and reliable manner. Toward that end, it is essentialthat the semiconductor or integrated circuit die be positioned andsecured within the temporary packages in an automated manner such thatdie bond pads are aligned with and suitably biased toward temporarypackage electrical contacts without physical damage to the diestructure.

SUMMARY OF THE INVENTION

The present invention provides computer-controlled methods and apparatusfor automating the positioning of integrated circuit devices or dicewithin temporary packages utilizing a high volume, continuous process.

Toward that end, the invention provides an automated apparatus for thepositioning of bare electronic dice within temporary packages that isused in-line with other machines to facilitate formation of assembledpackages which may then be subjected to continuity testing, burn-in andthe like.

The invention further includes methods and systems for accuratelypositioning electronic dice within temporary packages in a reliable,cost-effective manner. Accordingly, the invention provides methods andapparatus for continuous positioning of integrated circuit dice withintemporary packages in an automated production sequence whilesignificantly reducing the percentage of dice and temporary packageassemblies in which electrical continuity is not established. In sodoing, the invention employs multiple inspections of the dice andtemporary package prior to, during and after placement of the dicewithin the temporary package. By inspecting the dice at various stagesof assembly, dice which are not property aligned or positioned can berepositioned to ensure electrical continuity between all of the die bondpads and the contacts of the temporary package electrical conductors.The aforementioned inspections are preferably effected by multiplecameras to facilitate precise placement of the die in the temporarypackages in a continuous manner to significantly enhance the efficiencyof the assembly process and increase the number of packages in whichelectrical continuity is established.

In yet another aspect, the invention provides an apparatus for placingdice in temporary packages wherein the packages are supported oncarriers (also termed boats or trays, that are conveyed along a paththrough a predetermined package assembly/disassembly position. A carrierpreferably includes a body portion and at least one side rail having aplurality of spaced indexing openings therein. The carrier may be formedof plastic or metal. The conveyor portion of the apparatus furtherincludes an indexing mechanism that functions in conjunction with theindexing openings to place each temporary package in the predeterminedassembly/disassembly position to allow the integrated circuit die to bepositioned precisely therein.

The invention utilizes previously stored dimensional and visualcharacteristics for a die as well as similar characteristics of a knowntemporary package and a known boat or tray to assemble and disassembleelectrical dice and temporary packages respectively to and from oneanother based on predetermined parameters, and to classify the dieappropriately.

According to more specific aspects of the present invention, an assemblysystem is provided to place die bond pads in electrical communicationwith electrical contacts of temporary package conductors. Once the diebond pads are placed in secure communication with the package contacts,the temporary package can be placed in a standard device tester andsubjected to extensive testing. Such testing includes burn-in testingand the like to establish various die characteristics and eliminatemorality in subsequent use of the die. These characteristics, while notmeant to be limiting, include the quality of the electrical contactbetween the die and the temporary package conductors, as well as speedgrade characteristics by which the die itself may be classified.

The present invention includes a system which picks up and places aface-up die on a die inverter. The die is then inverted by the inverterand placed in the view field of a rough die camera, which takes apicture of the die. Using positional feedback from the rough diepicture, a robot having a primary gripper and also carrying a dieresting device (which may comprise a single or multi-component device)thereon retrieves the die from the inverter. The die is then presentedto a fine die camera by the robot and multiple pictures of the die aretaken to enhance resolution.

While the die is being located by the die cameras, a carrier (alsotermed a boat or tray, as previously noted) containing a plurality oftemporary package bases is simultaneously indexed to place a temporarypackage base located in the carrier in a predeterminedassembly/disassembly position along a conveyor. An electrical socketbelow the temporary package receives the leads of the temporary packagebase from below for electrical continuity testing. A rough temporarypackage picture is then taken of the temporary package base and used todetermine a rough location of the temporary package base at theassembly/disassembly position. In a preferred embodiment, a laser heightsensor may be used to determine the height of the temporary package baseat the assembly/disassembly position prior to taking fine package visionpictures, in order to keep the camera in focus. A fine temporary packagecamera is then positioned over selected electrical contacts of thetemporary package base at the assembly/disassembly position and multiplefine temporary package pictures are also taken to enhance resolution.

The die and die restraining device are then transferred by a primarygripper to the predetermined assembly/disassembly position. The robotaligns the die and temporary package base using the fine temporarypackage and fine die pictures, and presses the die, die restrainingdevice superimposed on the die, and package together to form anassembled test package which is then tested for continuity using theaforementioned test socket.

During the assembly process, the robot preferably drives the primarygripper carrying the die with the superimposed restraining devicedownwardly over the package base to a minimum programmed packageassembly interlocking height and tests the completed assembly forcontinuity. If continuity is confirmed, the robot then releases the dierestraining device and die. If continuity is not established, the robotincrements downward to a maximum programmed force setting. If continuityis still not established, the restraining device and die are removedfrom the package base. A new package base is placed in the predeterminedassembly position and the fine die, rough package, and fine packagepictures are retaken. The die with its associated restraining device andthe new temporary package base are then assembled and tested.

In an alternative embodiment of the present invention, the robot drivesthe primary gripper down until physical contact is established betweenthe die and the temporary package. After physical contact isestablished, the robot drives to a minimum programmed assemblyinterlocking height. The primary gripper then releases the die andassociated lid with the spring and clip of the restraining device andretracts to a waiting position. Electrical continuity of the assembly istested. If the assembly has electrical continuity between the die andthe temporary package base, the process is completed. If electricalcontinuity is not established, the primary gripper retrieves the die andrestraining device and awaits instruction from the operator. Theoperator may choose to retry assembly of the present temporary package,utilize the next available package base, or purge the die from thesystem and use the next die.

Any electromechanical device which is capable of transferring componentparts from one position to another may be used in the present invention.In a preferred embodiment, however, the transferring device is a robotarm. The apparatus has a control mechanism, including a microprocessorand associated program routines, that selectively controls the robot arm(i) to move the primary gripper to pick up a restraining device and (iflid and other elements of the restraining device such as a spring/clipcombination are separate components) to a lid feeder station to pick upa lid, (ii) to move the primary gripper along with the resting device topick up the die following photographing by the rough die camera, (iii)to move the primary gripper along with the restraining device and thedie to a position to be photographed by the fine die camera, and (iv) tomove the restraining device and the die to the predeterminedassembly/disassembly position located along the conveyor.

The control routines also function to return the primary gripper to thepredetermined assembly position and retrieve the die and restrainingdevice in the event that continuity is not established with thetemporary package base. The primary gripper then returns to select asecond lid, another restraining device spring/clip element (if separate)and a second die while the carrier is simultaneously indexed to placethe next temporary package base of the carrier in the predeterminedassembly/disassembly position along the path. The package assemblyprocess continues in this manner.

The present invention, as previously noted, also includes a method andapparatus for disassembling the electrical die and temporary packagebased on predetermined parameters or characteristics. The disassemblyprocess occurs in a manner substantially opposite the assembly process.In particular, a carrier boat or tray containing a plurality ofassembled temporary packages containing dice approaches thepredetermined assembly/disassembly position. Each package contains asemiconductor die which has been subjected to extensive testing. Theprimary gripper retrieves the electrical die and restraining device andplaces it on a die inverter which inverts the face-down die retrievedfrom the package base to a face-up position. The die is then placed inan appropriate location for further handling, depending upon whether theburn-in and other testing have proven it to be a KGD or a bad die and,if a KGD, of what classification. The lid of the resting device isreleased by the primary gripper and a lid precisor similar to the oneused for assembly is used to place the lid in a known location.

The foregoing discussion has merely highlighted some of the morepertinent advantages of the present invention. Such advantages should beconstrued to be merely illustrative of some of the more prominentfeatures and applications of the invention. Many other beneficialresults can be attained by applying the disclosed invention in adifferent manner or modifying the invention as will be described.Accordingly, other advantages and a fuller understanding of theinvention may be had by referring to the following detailed descriptionof the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference should be made to the following detaileddescription taken in connection with the accompanying drawings in which:

FIG. 1A is a plan view of an assembly/disassembly system forautomatically positioning dice within temporary packages in accordancewith the present invention;

FIGS. 1B-1C are side views of the assembly/disassembly system shown inFIG. 1A;

FIGS. 2A-2B are side and plan views, respectively, of a die pack feederfor use in accordance with the present invention;

FIGS. 3A-3C are side views of a wafer handier base having a transfermechanism which is suitable for use in the present invention;

FIG. 4 is a side view of a rough die camera which may be used in thepresent invention;

FIGS. 5A-5B are front and side views of a primary gripper of a robotarm;

FIG. 5C is an enlarged cross-sectional side view of a vacuum quillcarried by the primary gripper;

FIG. 6 illustrates a clip tray feeder for use in the present invention;

FIGS. 7A-7B illustrate plan and side views, respectively, of a lidfeeder station suitable for use in accordance with the presentinvention;

FIG. 7C is an enlarged view of the lid carousel illustrated in FIG. 7A;

FIGS. 8A-8B are plan and side views, respectively, of a lid precisorwhich is suitable for use in accordance with the present invention;

FIG. 9 is a plan view of the various components of an indexing mechanismfor use in accurately positioning the boat in the assembly/disassemblystation of the apparatus;

FIG. 10 shows a rough temporary package camera for use in accordancewith the present invention;

FIGS. 11A-11B illustrate side views of a fine temporary package cameraand secondary gripper which are suitable for use in accordance with thepresent invention;

FIGS. 12A-12B show an unclipping mechanism in a lowered position whichis suitable for use in the disassembly process of the present invention;

FIG. 13 illustrates a secondary inverter and die precisor for use in thedisassembly process of the present invention;

FIG. 14A, 14B and 14C illustrate plan, side and end views of a preferredtest or temporary package employed with the invention;

FIG. 15 is a plan view of a temporary package base with insert and diein place; and

FIGS. 16A, 16B and 16C, respectively, illustrate a top view of a carriertray with temporary package bases in place, a side view of a carriertray with assembled packages, and an end view of a carrier tray withassembled packages.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The inventive method and apparatus will now be described in conjunctionwith the continuous positioning of integrated circuit (semiconductor)dice within temporary packages. It should be appreciated that the use ofthe invention for this purpose should be considered merely exemplary andthat the techniques and mechanisms described herein can be used wheneverit is desired to accurately position, bond or attach dice.

In an exemplary embodiment, a method and apparatus are provided forautomatically positioning bare die 202 within temporary packages 300(FIGS. 14A-C) to facilitate extensive testing. As shown in FIG. 1A, theapparatus 10 generally includes platen or support surface 42, aprogrammable robot arm system 12, which preferably includes three arms12a, 12b and 12c, a wafer feeder station 14, die inverter 16, rough diecamera 24, a lid feeder station 22, lid precisor 26, fine die camera 30,a predetermined assembly/disassembly position 28, a clip tray feeder 50,and rough and fine temporary package cameras (not shown in FIG. 1A). Theassembly/disassembly position 28 is located along a conveyor 36 thatconveys a package carrier 180 (FIG. 16A) along a linear path indicatedby arrow 34 between a first position, corresponding to inlet 38, and asecond position, corresponding to outlet 40. The die and restrainingdevice and base of the temporary package are assembled atassembly/disassembly position 28 as will be described more fully herein.

It should be appreciated that each carrier 180 enters the apparatus atthe inlet 38 and then travels along the path through theassembly/disassembly position 28 where the dice are positioned withinthe package bases 302 (FIG. 16A) in the carrier 180. The continuitybetween the die 202 and temporary package conductors is preferablyevaluated at assembly/disassembly position 28. Thereafter, the carrier180 with temporary packages 300 containing bare die 202 to becharacterized is conveyed through the outlet 40 and the die 202 is thensubjected to additional testing as previously mentioned.

Although not shown in detail in FIG. 1A, it is desired that a pluralityof carriers 180, each supporting a number of temporary package bases 302(see FIG. 16A), be continuously supplied to conveyor 36. While not meantto be limiting, this can be accomplished by the use of a carrier inputelevator 38a and carrier output elevator 40a. A new carrier 180 issupplied at the inlet 38 after all package bases 302 in a previous boatlocated at the assembly/disassembly position 28 have been indexedthrough predetermined position 28. Die 202 and restraining devices 304(FIG. 5A), such as lids and/or clips, are then supplied to the packagebases 302 contained in the new carrier 180. Appropriate sensor andindexing assemblies are located at the inlet 38 and outlet 40 of theconveyor 36 to control the movement of carriers 180 thereon, supply ofcarriers 180 thereto and removal therefrom.

Conveyors, such as those manufactured by Flexible Technology located inRichardson, Tex., are suitable for use in the present invention. Otherconveyors, such as flat belt conveyors, timing belt conveyors, walkingbeam mechanisms and the like are also suitable for use in the presentinvention. The conveyor is controlled by a suitable electric motor andgearing mechanism, as is well-known in the art.

As described generally above, a plurality of cameras is used inaccordance with the present invention to ensure precise placement ofdice within temporary packages. While not meant to be limiting, oneembodiment of the present invention utilizes five cameras or imageproducers. As will become apparent, a first camera is used to accuratelylocate the initial position of a wafer and individual die before the dieis moved. Two additional cameras (rough and fine) are used to locate thedie and the remaining two cameras (rough and fine) are used to locatethe temporary package base in order to assemble a device under test(hereinafter "DUT"). The present invention uses rough cameras to locatethe die's and package base's general positions such that the die andbase can each be positioned in the respective fine cameras' fields ofview. Preferably, the fine cameras have fields of view in the range ofabout 0.0020". In an alternative embodiment, three cameras are utilized,namely, a first camera to accurately locate the position of a wafer andindividual die thereof, a die camera and a temporary package camera.

The basic operating method of the automatic die placement apparatus willnow be described. FIGS. 1A-1C show an assembly system 10 forautomatically positioning dice within temporary packages in accordancewith the present invention. Wafers 200, which have been previouslytested to select dice from a wafer map or ink dot, are positioned inwafer feeder station 14. The wafers 200 may have previously been dividedinto individual dice 202. Alternatively, singulated (individualized)dice 202 may be supplied by die pack feeders 48a-48c.

FIGS. 2A-2B illustrate side views of a 2×2" die pack feeder 48b. The diepack feeder 48b includes die pack input 60 and output 66, die shuttle 62and pneumatic cylinder 64. Alternatively, a 4×4" die pack feeder may beused or, as shown in FIG. 3. 1A, a 2×2" die pack feeder 48b and a 4×4"die pack feeder 48a may both be utilized. Die pack feeders 48b areparticularly suitable for use in the invention when singulated dice aresupplied to apparatus 10. Die packs 190 (also known as "gel packs") areplaced into input 60 and one pack 190 is then moved on shuttle 62 bypneumatic cylinder 64 into the workcell area. Dice 202 are then placedinto or taken out of the die packs 190. When the loading or unloadingprocess is completed, shuttle 62 carrying the die pack 190 is moved bypneumatic cylinder 64 to output station 66, where it is removed andshuttle 62 returns to input station 60 to receive another die pack 190.

Alternatively, a wafer handler base 170, as illustrated in FIGS. 3A-3C,may be used when the dice are supplied in wafer form 200 (FIG. 1A).First camera 20, as shown in FIG. 1A, is preferably positioned overlocation 18. Location 18 corresponds to a die transfer position. Firstcamera 20 is preferably located to look down at the film frame andsuperimposed wafer 200. First camera 20 first determines the exactposition of the wafer 200 on the film frame by looking for combi marksor fiducial marks on the wafer. The camera 20 then takes a picture ofeach die of the wafer 200 to verify that the die is there, to verifythat there is no ink dot on the die, and to locate the die's exactposition to account for any change in position when the film frame isstretched to slightly laterally separate the die for retrieval.

Die transfer arm 70, shown in FIGS. 3A-3C, of the present inventionpicks up a die 202 from wafer 200 at location 18 and places the die 202on die inverter 16. The die is then inverted by die inverter 16, placedon die pedestal 74 and brought into view of rough die camera 24. Whilenot meant to be limiting, die 202 is picked off of wafer handler base170 or die pack feeder 48b using a vacuum quill 71 (see F G. 3C)translated by pneumatic cylinders. The cylinders are reciprocated insuch a manner that the die is transported and placed on die inverter 16.

Rough die camera 24 is preferably located on base 42 behind id feederstation 22 (see FIG. 1A). As shown in FIG. 4, rough die camera 24includes a CCD (Charge Coupled Device) camera 80, lens 82 and prism 72.CCD camera 80, which is preferably located behind lid feeder station 22,looks up at the die 202 through prism 72 and pedestal 74 to determinethe general position or location of the die 202 so that robot arm system12 using primary gripper 52 may retrieve and place the die 202 withinthe field of view of fine die camera 30. Prior to rough die camera 24taking a picture, the die 202 is preferably illuminated withbacklighting. Rough die camera 24 then takes a picture of the die atpedestal 74.

The rough die picture is analyzed utilizing a computer program todetermine the rough position of the die. A blob finder is used to locatethe centroid of the die, which is held on the pedestal 74. The blobfinder analyzes the binary (black/white) picture of the die andpedestal. Based on the position of the centroid, an edge finding ruleris utilized in the negative Y direction (away from the pedestal) inorder to locate the bottom edge of the die, as referenced in the visionwindow. A line finding box is then used at the bottom edge of the die tolocate the angle of the bottom die edge.

The size of the die being manipulated is preferably known and stored inthe data file in binary form (IGES format in particular, although othertext file formats may be employed) associated with that die. An edgefinding ruler is utilized in the negative X direction relative to thevision window. The edge finding ruler starts in the centroid of the dieand is used to locate an edge of the die perpendicular to the edgelocated above. A line finding box is used at the perpendicular edge tolocate the angle of the side edge. Once the angle and location of twoperpendicular sides of the die is determined, two edge finding rulersare placed over the image. One ruler is placed across the die in orderto measure the width of the die. The second ruler is placedperpendicular to the first ruler to find the length of the die todetermine the exact size of the die. The center position of the die iscalculated, using the average of the angles obtained above.

Using positional feedback data from the computer and rough die picture,robot arm system 12 then orients primary gripper 52 to the die. As shownin FIGS. 5A-5B, primary gripper 52 preferably includes vacuum quill 90,linear slide 92 and suction cups 94. Primary gripper 52, which has arestraining device 304 attached thereto, retrieves the die. While notmeant to be limiting, the restraining device may be a bridge clip, aclip and lid, screw or combination thereof. When lids 306 are used withbridge clips 308 as the restraining device (see FIG. 14A), lid transferarm 54, shown in FIGS. 7A-7B, selects a lid 306 from lid feeder station22 and presents the lid 306 to mechanical lid precisor 26. Lid precisor26 is used to place lids 306 in a known location.

In a preferred embodiment, lid feeder station 22 supports a plurality oflids 306 in multiple vertical stacks on a rotatable carousel 100, shownin FIG. 7A. As the lids 306 are exhausted from each stack in thecarousel, the carousel 100 rotates to present a new stack to the lidtransfer arm 54. When all stacks of the carousel 100 are exhausted, thecarousel 100 may be rotated away from the lid transfer arm 54 and a newcarousel 100 provided by the operator.

FIGS. 7A-7B illustrate lid feeder station 22, while FIG. 7C depicts aplan view of a lid carousel 100 for use in the present invention.

As mentioned above, lid transfer arm 54 selects a lid 306 from lidfeeder station 22 and presents the lid 306 to lid precisor 26. FIG. 8Aillustrates a plan view of lid precisor 26, while FIG. 8B depicts a sideview of lid precisor 26. Lid precisor 26 includes a vacuum chuck 110,pneumatic cylinder 112 and precisor block 114.

The bridge clip 308 (FIG. 14A) secures the die in the temporary packageduring testing. Bridge clips 308, which may have various configurations,provide physical connection of the tops of the temporary packages to thebases thereof. The aforementioned U.S. Pat. No. 5,367,253 to Wood et al.discloses a suitable bridge clip configuration in FIG. 1B thereof, and amore detailed description of all of the components of temporary package300 and package carrier 180 appear hereafter. FIG. 6 illustrates a cliptray feeder which is suitable for use in the present invention. Morespecifically, clip tray feeder 50 preferably includes an elevator 120which carries a stack of clip trays for presentation to the machine.Each tray is individually removed and pulled into the robot's workvolume by the tray presentation arms (not shown). The clip tray feeder50 will utilize different styles of clips by utilizing optional cliptrays. The restraining device may include a clip, a clip and a lid or aclip/lid combination which are formed as a unit and used in conjunctionwith a die. Preferably, however, the clip is a bridge clip 308 which ispicked up by the primary gripper 52 before the lid 306 or the die. Thelid 306 is placed on the vacuum chuck 110, shown in FIGS. 8A and 8B. Thepneumatic cylinder is actuated, pressing the precisor block 114 againstthe lid. This action puts the lid into a location that is "known" torobot arm system 12. It should be appreciated that the present inventionis not limited to a restraining device which includes clips and lids.Any method of restraint is possible. For example, screws, adhesives orthe like may be substituted for, or used in addition to, clips.

In an alternative embodiment, the restraining device need not be pickedup. Rather, the resting device may be attached to or be an integral partof the temporary package base.

After the die 202 has been picked up by the primary gripper 52, the die202 is then presented to fine die camera 30. Fine die camera 30 ispreferably located on base 42 near conveyor 36 so that it looks sidewaysthrough a prism, up at the die 202 in an arrangement similar to that ofrough die camera 24. The base 42 of apparatus 10 may be constructed ofmetal, granite or a vibration isolation table. !Base 42, however, ispreferably formed of granite. A granite base provides stability, whichis critical for precision and accuracy. Fine die camera 30 determinesthe precise location of the die 202 and takes multiple pictures of thedie 202 such that the die bond pads and electrical contacts of thetemporary package base can be properly aligned.

More specifically, the die 202 is secured and opposite corners of thedie are presented to the fine die camera 30. The following algorithmdescribes the analysis done for each corner of the die. First, a binarypicture of the die corner is taken. The binary picture is used for allsubsequent analysis steps. Two-edge finding rulers are positioned acrossthe width and height of the screen in order to locate the edges of thedie features (Vbb ring, bond pad, etc.) specified. Once the two edgesare located, line finding boxes are placed at the transition points ofthe edges of the die features. These are used to locate the angle of thedie corner. The angles and points are used to mathematically calculatethe corner point of the die etching in the field of view of the camera.The X and Y position of the corner point is the only information usedfrom the fine die picture.

Once the die X and Y points of two opposite corners are known, twoadditional pictures are taken in order to precisely determine the angleof the die. The pictures are taken by placing two opposite features ofthe die in front of the camera. The features are on the same side of thedie. Thus, by locating two points of the etching along the same side ofthe die, the angle of the die relative to the angle of the gripper canbe calculated.

A picture is taken and the binary picture is used for all subsequentanalysis steps. An edge finding ruler is utilized from the top of thevision window in the negative Y direction in order to locate the etchingof the die. At the point where the etching is located, a line findingbox is placed across the screen, perpendicular to the edge finding rulerin order to verify that the edge of the die has been located. Thisinformation is later used to position the die in proper alignment withthe temporary package base.

While pictures are being taken by fine die camera 30, a carrier or boat180 with temporary package bases 302 positioned therein is brought intoassembly/disassembly position 28 in the direction of arrow 34 shown inFIG. 1A. The carrier is conveyed along conveyor 36 between the inlet 38and the outlet 40, but is positioned to stop at predeterminedassembly/disassembly position 28. Appropriate sensor and indexingassemblies are located at the inlet 38 and outlet 40 of conveyor 36 tocontrol the movement of the carriers thereon.

Each carrier or boat 180 (see FIGS. 16A-16C) includes a body portion 182and a pair of side rails 184. The side rails preferably include aplurality of spaced positioning or indexing holes 186. As seen in FIG.9, an indexing mechanism 400 includes a through-beam sensor 402 mountedon one rail 404 of conveyor 36 and a locking mechanism 32 supported onthe opposite rail 406. The through-beam sensor includes an LED andphototransistor for counting the number of spaced positioning holes inthe side rail of the carrier.

When a predetermined number of indexing holes 186 have been counted,locking mechanism 32 is actuated to drive a plunger 408 into one of theholes 186 to lock the carrier 180 into position. As long as the numberof holes 186 and their relative spacing is known, it is thus possible touse the indexing mechanism 400 to control the selective movement of thecarrier 180 through the assembly station regardless of the size of thecarrier 180 or the number of packages 300 or bases 302 therein.

Each carrier 180 supports a number of temporary package bases 302 orassembled temporary packages 300, again according to whether an assemblyor disassembly sequence is in order. For example, carriers containingfive or ten temporary packages are suitable for use in the presentinvention. While the number of temporary packages in a carrier may varyand while not meant to be limiting, it has been found that fourtemporary packages in one carrier oriented transversely to direction 34is a number particularly well suited for use in accordance with thepresent invention. Assembled temporary packages 300 are preferablyplaced in contact with a socket container to verify that there win beelectrical contact between the die of the temporary packages 300 andburn-in boards, load boards, and the like during subsequent burn-in andother testing. While not meant to be limiting, the socket preferablyraises up in position 28 to receive the leads of a package 300 and toverify electrical continuity. However, any method of insuring contact issufficient. For example, an electrical socket 162, shown in FIG. 12B,may be plugged into each temporary package for continuity testing at theassembly/diassembly position 28 to test the die and the temporarypackage for electrical continuity during assembly. Each opening in thecarrier for receiving a temporary base 302 is flanked by a pair oflocking slots which secure restraining devices such as clips attached tothe die to temporary packages in a carrier.

The present invention includes a general purpose computer control systemfor controlling the operation of the apparatus 10. The control systemincludes one or more work stations having a microprocessor havingassociated storage, appropriate operating system and control programs,and suitable I/O devices (such as a keyboard, mouse, display andprinter). The apparatus further advantageously uses a robot arm systemthat is controlled by a special purpose computer control system.Although not meant to be limiting, preferably the robot is a 4-axisGANTRY robot arm, which is commercially available from Adept Technology,Incorporated, located in San Jose, Calif. The robot arm is controlled byassociated control software routines that effect sequential movements ofthe robot arm in accordance with the processing steps.

Although not shown in detail, it should be appreciated that the variouscontrol mechanisms of the apparatus are selectively controlled bysuitable actuators under the control of software programs resident inthe control microprocessors. Such control mechanisms are well known inthe art.

The present invention further includes two temporary package cameras orDUT cameras as illustrated in EGS. 10 and 11A. A rough temporary packagepicture is taken by the rough temporary package camera 130 shown in FIG.10 to locate the temporary package 300 or package base 302 in thecarrier. The rough temporary package camera 130 includes a CCD (chargecoupled device) camera 132 and lens 134. The rough temporary packagepicture is analyzed to determine the rough location of the temporarypackage. While not meant to be limiting, the height of the temporarypackage is preferably determined by a laser height sensor, such as thatmanufactured by OMRON, being placed over the temporary package.

The rough temporary package or DUT camera 130 is preferably located onthe Z axis of robot arm 12c and positioned to look down at the temporarypackage base 302 of the temporary package 300. The rough temporarypackage camera 130 determines the D1UT base's general position in thecarrier so that fine DUT camera 140 can move into correct position.

A picture is taken by camera 140 and the binary picture is used for allsubsequent analysis steps. Six rulers are utile, starting at the top ofthe vision window in the negative Y direction. Once the rulers areplaced, the closest transition is taken to be the major line of thetemporary package electrical interconnects. A line-finding box is placedperpendicular to the rulers at the transition point in order to locatethe angle of the major line of electrical interconnects. From the data(IGES) file, the following parameters are known: (a) the X distancebetween the fiducial mark and the major line of the temporary packageand (b) the side of the temporary package where the fiducial mark islocated.

A transition finding ruler is placed across the package to locate thefiducial mark. A blob finding box is placed around the fiducial mark inorder to precisely locate the fiducial centroid. Once the centroid islocated, the center of the temporary package and the location of theelectrical interconnects or contacts that the die is to be aligned withare calculated utilizing the data file information.

Using the rough temporary package picture analysis and the height sensorresults, fine temporary package or DUT camera 140, as illustrated inFIG. 11A and in FIG. 11B, is positioned over the selected electricalinterconnects utilizing robot arm system 12. Fine DUT camera 140 islocated on the Z axis of robot arm system 12 adjacent primary gripper 52(shown simplified form in FIGS. 11A and 11B) and looks down towards thetemporary package. Fine DUT camera 140 determines the precise locationof the temporary package base 302 so that the bond pads of the die canbe properly aligned with the designated contacts of the temporarypackage base 302. Fine DUT camera 140 preferably takes at least onepicture at each end of the package base 302. In a preferred embodiment,a secondary gripper 142, such as that shown in FIGS. 11A and 11B, isalso included. Secondary gripper 142 includes a vacuum quill 141, linearslide 143 and pneumatic cylinder 145 and is used to transfer dice thatare presented after completion of testing in DUT's to the die packfeeders 48a-48c.

Robot arm system 12 moves the fine temporary package camera 140 over theuser-specified electrical contacts of the temporary package base 302. Ifthe temporary package base is built to specifications and the roughtemporary package location process was successful, the chosen electricalcontacts of the package base should be placed in the center of the fieldof view of fine DUT camera 140.

A picture is taken of the package base's electrical contact pattern anda copy of the picture is created. The second copy of the picture is"added" to the original picture, preferably four times. This method istermed GRAYSCALE ADDITION. This has the effect of isolating thetemporary package features and "whiting out" the rest of the picture.The modified GRAYSCALE picture is then converted to a binary picture. Ablob finder box is placed across the whole picture in order to locateall electrical contacts in the picture. The electrical contact closestto the center of the picture is selected and an arc-finding circle isplaced around that point with the same diameter as the electricalcontact pattern. This locates the center of the electrical contactpattern.

Using the fine temporary package pictures and the fine die pictures,robot arm system 12 aligns the die and temporary package base andpresses the two together, thereby creating a completed assembly with thepackage lid and restraining device. During the assembly process, robotarm system 12 preferably drives to a minimum programmed assembly lockingheight and tests the completed assembly for electrical continuity. If,continuity is confirmed, robot arm system 12 then releases therestraining device or devices and die. If however, continuity is notestablished, the robot arm system increments to a maximum programmedforce setting. If continuity is still not established, the restrainingdevice (including lid, if separate) and die are removed from thetemporary package. A new package base is then positioned and the finedie, rough temporary package, and fine temporary package pictures areretaken and the die, restraining device and new temporary package baseare reassembled.

In an alternative embodiment of the invention, the assembly processincludes robot arm system 12 driving until physical contact isestablished between the die and the temporary package base. Afterphysical contact is established, robot arm system 12 drives to minimumprogrammed assembly interlocking height. The primary gripper 52 releasesthe lid and/or clip (restraining device) and the die and then retractsto a waiting position. Electrical continuity of the assembly is tested.If the assembly has electrical continuity between the die and thetemporary package, the process is completed. If electrical continuity isnot established, the primary gripper 52 retrieves the die, lid and/orrestraining device components and awaits instruction from the operator.The operator then decides whether to retry the present package, utilizethe next package, or purge the die from the system and use the next die.

As mentioned above, the present invention utilizes two computer memoryfiles to determine which features on the die and package base will belocated and positioned for alignment. Such an approach, using pre-storedrepresentations of surface features of the die and package base, permitsthe vision system to look for, find and orient the required surfacefeatures on the actual objects to be aligned, and to subsequentlyexecute the alignment, electric continuity test and clip attachmentoperation without operator intervention or other interaction. While notmeant to be limiting, preferably the files are IGES files containingdrawings of the face of the die and of the contact area of the packagebase. However, any file such as DXF or the like which is capable of CADdata transfer is suitable for use in accordance with the presentinvention. One file is employed for the die and the other for thetemporary package base. Any CAD program is suitable for use to createthe drawings, but the drawings are preferably saved in the file format.

The package base and die drawings should mirror one another, i.e. if onedrawing were placed face-down on top of the other, the selected featuresfor alignment should be superimposed.

By taking pictures of the diagonally-opposed ends of each of the diceand temporary package, and using an algorithm, a die can thus beprecisely positioned within a temporary package base in a fraction ofthe time required by prior art techniques. For example, prior arttechniques employed in DUT assembly require approximately four minutesto assemble a die in a temporary package. The present invention iscapable of positioning a die in a temporary package in about 30 secondsand does so in a manner which is more precise and reliable than thosetechniques used in accordance with the prior art. Moreover, the methodsand apparatus of the present invention provide for improved positioningof the die bond pads relative to the temporary package electricalinterconnects than obtained using prior art techniques.

The present invention also includes a disassembly process fordisassembling the die from the temporary package. The disassemblyprocess is substantially the opposite of the assembly process. Dice intemporary packages 300 which have been subjected to testing enter thedisassembly apparatus 13 in carriers 180 on conveyor 36 as in theassembly process. Carriers 180 are indexed through the apparatus 10 andare designed to proceed to predetermined disassembly position 28 as inthe assembly process.

Referring now to FIGS. 12A-12B, an unclipping mechanism 150 is shown.Unclipping mechanism 150 is preferably positioned along conveyor 36 nearpredetermined assembly/disassembly position 28. As shown in FIGS.12A-12B, unclipping mechanism 150 includes a pneumatic parallel jawactuator 152, clip release fingers 154, a pneumatic cylinder 158 and alinear slide 160. FIG. 12A depicts the unclipping mechanism 150 in alowered position in which the electrical test socket 162 disconnectsfrom the temporary package. Prior to unclipping, the primary gripper 52is placed by the robot arm system 12 into contact with the clip and/orlid and die. Clip release fingers 154 of the unclipping mechanism 150,which is raised prior to unclipping, releases the clip from theassembled package for recycling of the clip to the clip tray feeders.Mechanism 150 has, however, been superseded by a gripper-mountedactuator as subsequently described herein.

The clip, lid and die are then removed from the temporary package byprimary gripper 52 and moved to disassembly inverter 44, shown FIGS. 1Aand 13. The die is placed on disassembly inverter 44, which is similarto die inverter 16. The inverted die is then reinverted such that thedie is face up on disassembly precisor 46, which is similar to precisor26 utilized in the assembly process.

The die is moved to one of the die pack feeders stations 48a-48c usingsecondary gripper 142 based on predetermined characteristics of the die.For example, dice having a certain grade or quality may be transportedto station 48a for placement in a die pack 190, while dice having adesignated speed grade characteristic are transported to station 48b.Station 48c is generally reserved for dice which are rejected, i.e. dicewhich do not meet minimum characteristics. In this manner, the dice areremoved and classified according to predetermined characteristics forlater assembly in component packages. Additional stations may also beincluded to further categorize or separate the dice based on variousproperties.

After the die is removed from the carrier 180 and is being subjected toinversion by disassembly precisor 46, the carrier is simultaneouslyindexed such that the next package in the carrier 180 is moved intopredetermined assembly/disassembly position 28. In this manner, thedisassembly process is continuous. After all of the dice are removedfrom the carrier 180, the carrier 180 continues along conveyor 36 tooutlet 40, while the next carrier enters inlet 38.

It may prove beneficial to those of ordinary skill in the art to receivea more detailed description of the components of a preferred embodimentof primary gripper 52 and their respective functions, particularly inconjunction with a preferred embodiment of the temporary or test packageemployed with the apparatus of the present invention and manipulated bythe method thereof, the preferred embodiment of package 300 being thatof the aforementioned U.S. Pat. No. 5,367,253 to Wood et al.

Referring now to FIGS. 14A-14C, 15 and 16A-16C of the drawings,temporary or test package 300 generally corresponds to that depicted inFIGS. 1A-1C, 2 and 5A-5C of the '253 patent. However, reference numeralsas previously employed herein are used for clarity. FIGS. 14A-14C depicta carrier 180' adapted to hold only a single package 300.

Preferred carrier 180 (see FIGS. 16A-16C) supports a plurality of diecavity plates 302, also referenced herein for simplicity as temporarypackage bases. Base 302 includes a cavity 310 therein and a plurality ofexternal terminals or leads 312 extending therefrom. In an exemplaryembodiment, base 302 takes the form of a ceramic DIP (dual in-linepackage), although other configurations, such as a QFP (quad flat pack)are certainly suitable. Carrier 180 carries a plurality, preferably four(4), of bases 302 during the sequence in which an untested die 202 isinserted into cavity 310 in alignment with base 302 for electricalcommunication with leads 312 for electrical testing and burn-in. Aspreviously noted, carriers 180 include positioning holes 186 in siderails 184.

As shown in FIG. 15, bond pads 204 of die 202 are aligned with contacts314 of ceramic die insert 316, which is mounted to base 302. Contacts314 are located at the inner ends of conductors or circuit traces 318,the outer ends 320 of which are electrically connected by wire bonds towirebond pads 322 on base 302, wirebond pads 322 being in electricalcontinuity with leads 312 extending from base 302 through internalconductors as known in the art. Insert 316, which may also be flexibleor semi-rigid and of another material other than ceramic, such aspolyimide, is employed to adapt packages 300 to a variety of die sizesand bond pad configurations.

Cover or lid 306 is employed superimposed over die 202 (FIG. 14B) and abridge clamp or clip 308 employed thereover to secure die 202 betweeninsert 316 and lid 306 with bond pads 204 aligned with contacts 314 asassembly of package 300 is completed. Bridge clip 308 is mechanicallyengaged with carrier 180. Clip 308 includes clip ears 344 havingprotruding tab catches 326, which may engage with a pair ofcorresponding slots 328 flanking each package base 302 on carrier 180.Leaf spring 330 presses against the top of Lid 306 when catches 326 areengaged with slots 328, biasing bond pads 204 of die 202 into ohmiccontinuity with contacts 314 Of insert 316. Clip 308 and spring 330include aligned superimposed apertures 332 therethrough which arealigned (when lid 306 is picked up) with a smaller aperture 334 throughlid 306. The purposes of these structural features will be furtherexplained below in connection with operation of primary gripper 52 inthe package assembly and disassembly sequences of the present invention.

Referring again to FIGS. 5A and 5B of the drawings, primary gripper 52includes vacuum quill 90 supported on linear slide 92, also referred toas a quill slider base. Bridge clip vacuum cups 94, which flank vacuumquill 90, are in communication with an active vacuum system, as known inthe materials-handling art. Clip arm actuator 340, includingdownwardly-extending clip arms 342, is also carried by primary gripper52. Actuator 340 may comprise a Schunk parallel-jaw actuator; however,other brands and designs would also work.

Clip arms 342 are inwardly- and outwardly-movable, and are employed tobias clip ears 344 of bridge clip 308 inwardly during the packageassembly and disassembly process so as to pass through slots 328 withouttouching the carrier 180 and potentially causing misalignment of packagecomponents and attendant damage to die 202. After bridge clip 308 isextended to its assembly position, clip ears 344 are released by arms342 so that tab catches 326 secure clip 308 to base 302.

During the package assembly sequence, bridge clip 308 is held to thelower end of gripper 52 by vacuum cups 94 and by clip arms 342 in theirinward position. The vacuum cups 94 permit pickup of the clip 308without gripper 52 coming to a hard stop, as only cup contact isrequired to pull a clip from a clip tray feeder 50. Further, the use ofoptional clip locator pins 346, in combination with the vacuum force ofcups 94, gently locates clip 308 via clip apertures 309 with respect togripper 52 without forcing clip 308 onto gripper 52. Since thepositioning system of the invention requires alignment tolerances ofless than 0.001 inch, soft alignment is extremely beneficial. The vacuumcups 94 also "tell" the apparatus when a clip 308 is present or absentvia a vacuum sensor communicating with the vacuum system extending tocups 94.

Vacuum quill 90, extending downward from the gripper body (and through aclip 308 when such is secured to gripper 52), is employed to hold a lid306 and die 202 with vacuum during package assembly and disassemblyoperations. Quill 90 is long enough to extend below the spring of clip308 so that the spring does not contact the lid except when the package300 is being assembled and the spring is compressed. Linear slide 92 towhich quill 90 is mounted permits vertical movement of quill 90 duringplacement of die 202 on and removal of die 202 from a package base 302,and may comprise any commercially available crossed roller type oflinear bearing, such as a THK cross roller table. Linear slide 92 ismounted to gripper 52 in such a manner that the quill 90 may be centeredwith respect to a package or base, and to adjust the quill's verticalalignment so that it is perpendicular to a package or base. Suchadjustments are desirable to prevent damage to a die and to the packagecomponents during assembly and disassembly operations. It should benoted that slide 92 is a passive, e.g., unmotorized component andprovides the ability but not a drive for vertical quill movement.

Quill 90 (see FIG. 5C) holds both a lid 306 and a die 202 during anassembly or disassembly sequence. An inner axial vacuum channel 350 andan outer, independent annular vacuum channel 352 are provided, withcoaxial but separate openings 354 and 356, respectively. Opening 356holds lid 306 to quill 90, while opening 354 supplies a vacuum to lidaperture 334. The aperture 334 is then used to hold a die 202 to thebottom of the lid 306. Quill 90 is press fit into quill holder 360,which serves as a bracket to mount quill 90 to linear slide 92 and toprovide a manifold to supply vacuum to the two vacuum channels 350 and352. As with the clip holder vacuum system, vacuum sensors are employedwith the lid and die vacuum systems to provide feedback as to whetherthe relevant component is present or absent from the gripper 52.

In operation, a temporary package base 302 is secured to a carrier 180.primary gripper 52, carrying the above-referenced vacuum and actuatorarm assemblies, moves to a clip tray feeder 50 and stops over a bridgeclip 308. Arm 12c moves downwardly until the top surface of the clip 308in question is contacted by clip vacuum cups 94. Vacuum is then appliedto firmly attach clip 308 to cups 94. At the same time, the vacuum cupsbellows collapse upwardly, shortening the vertical length of the cups 94and pulling the clip 308 up out of the clip tray and onto the cliplocator pins 346 to align clip 308 with respect to gripper 52.

The clip arms 342 of actuator 340 then move inwardly, in turn movingclip ears 344 inwardly to permit ears 344 to move through slots 328 oncarrier 180 as the clip 308 is secured over package base 302.

Arm 12c then moves over lid feeder station 22 and lowers gripper 52until the lowermost part of quill 90 touches the top of a lid 306.Vacuum is then supplied to outer channel 352 and opening 356 to hold thelid 306 to the quill 90. Arm 12c, with attached clip 308 and lid 306,then moves gripper 52 over a bare, face-down die 202 which has beenremoved from a wafer 200 and then inverted, or provided from a gel pack190. Vacuum is supplied to inner channel 350 and opening 354 of quill 90to hold die 202 to the bottom of lid 306 through aperture 334.

Gripper 52 is moved upward and positioned over fine die camera 30 forlocation of specified features on the active or circuitry side of die202, such as the length, width and angular orientation (with respect tothe Z-axis) of the die 202 and the pattern and location of bond pads 204and other circuit elements of the die. The die 202 is then aligned witha package base 302 carried by a carrier 180 using vision techniquesincluding a pattern recognition system as previously discussed.

After die to package base alignment, the gripper 52 is moved down untilthe die bond pads 204 make physical contact with the electrical contacts314 of package insert 316. Gripper 52 moves further downward to extendthe tabs of clip ears 344 into slots of carrier 180 for clip retentionto package base 302. As the apparatus moves downward, linear slide 92 isforced relatively upward and maintains a biasing force against lid 306and die 202, which holds the die 202 firmly in place against the packageinsert contacts 314. The quill biasing force is necessary to ensurenon-movement of die 202 while leaf spring 330 of clip 308 contacts thetop surface of lid 306 prior to the engagement of cup ears 344 withcarrier 180.

The last assembly sequence step is outward movement of clip ears 344 toengage with the package 300 and the carrier 180. As robot arm 12creaches its lowest vertical position, actuator 340 moves arms 342outwardly to permit the tab catchers 326 of ears 344 to engage with theslots of carrier 180. Substantially simultaneously, the vacuum to cups94 and quill 90 is terminated. Arm 12c then moves gripper 52 upward torepeat the cycle. The bridge clip 308 is thus secured over the packagebase 302, sandwiching the lid 306 and die 202 between the spring 330 ofthe clip 308 and the insert 316 carrying the contacts 314 of the packagebase 302.

As shown in FIGS. 16B and 16C, after a carrier 180 is filled with DUT's,a protective cover 370 is optionally placed over support columns 372 andsecured in place by pin 374.

It should be noted that what is currently preferred and understood bythe inventors to be the best mode of practicing the invention employs acarrier structure disclosed and claimed in U.S. Pat. No. 5,519,332. The'332 patent employs a base which is engaged by a bridge clip, ratherthan the package carrier being so engaged. However, the engagementmechanism (slots receiving tabbed arms of the bridge clip) is the sameas disclosed herein. Thus, the description of the assembly anddisassembly sequences set forth herein are equally applicable to thecarrier structure of the '332 patent, and no further description thereofis required.

Disassembly of a package 300 follows the same procedures describedabove, except obviously in reverse, wherein arm 12c commencesdisassembly by extending gripper 52 over a package 300. Actuator arms342 inwardly compress clip ears 344 and gripper 52 pulls die 202, lid306 and clip 308 upward away from package base 302 and carrier 180 usingvacuum for the die 202 and lid 306 and vacuum and actuator arms 342 tohold clip 308. Tested die 202, lid 306 and clip 308 are then placed asdesired in suitable receptacles at predetermined locations for furtherhandling.

The foregoing system is adapted for handling and KXG qualification of awide variety of dice. For example, dice from 0.100×0.200 inch up to1.0×1.0 inch, with thickness raging from 0.010 to 0.030 inch, may beaccommodated. Dice to insert placement, as measured from geometriccenter of the die bond pad 204 to the geometric center of the insertcontact 314' is within 18 microns, including total system variations dueto accuracy and repeatability, with die and insert input data (IGESfile) located to plus or minus 0.5 micron. Lot tracking of all materialsemployed, including wafers and DUT's, is effectuated by bar coding.Units per hour throughput, referenced above as about 120 per hour (onedie-to-package assembly per 30 seconds), will ultimately exceed 300 perhour.

It should be appreciated by those skilled in the art that the specificembodiments disclosed above may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present invention. For example, other known uses forthis type of technology include, but are not limited to, flip chip diebonding, chip on board bonding, any high accuracy die attach process,and known good die assembly utilizing any temporary carrier technology.Additionally, it is within the scope of the invention to assemble thedie in the package such that testing is done with the die being in anupright position rather than in an inverted position. The die may thenbe inverted during disassembly or alternatively remain in an uprightposition. It should also be realized by those skilled in the art thatsuch equivalent constructions do not depart from the spirit and scope ofthe invention as set forth in the appended claims.

What is claimed is:
 1. An apparatus for automatically positioning a diewithin a test package having first and second mutually cooperativesections, comprising:a movable transport assembly bearing a test packageassembly mechanism configured to engage said second section of said testpackage and manipulate said second section of said test package tosecure said second section of said test package in said mutualcooperation with said first section, said test package assemblymechanism including a vacuum lifting element configured to extendthrough said second section of said test package when said secondsection of said test package is engaged by said assembly mechanism tolift said die for movement by said transport assembly in concert withsaid second section of said test package; a first imaging assemblyoperable to provide an image output signal of said die; a second imagingassembly operable to provide an image output signal of said first testpackage section; and a controller assembly operable in response to aprogram stored in machine-readable media, said controller assemblyoperably coupled to received said die image output signal and said firsttest package image output signal and to control a position of saidtransport assembly at least partially in response thereto to positionsaid die and said second test package section in relationship to saidfirst section of said test package and to cause said test packageassembly mechanism to manipulate said second section of said testpackage to effect securement of said second section of said test packagein said mutual cooperation with said first section with said diedisposed therebetween.
 2. An apparatus for automatically positioning adie within a test package having first and second mutually cooperativesections, comprising:a translatable transport assembly includingstructure for holding said second section of said test package and avacuum die lift element, said transport assembly being configured toposition said die below said second section of said test package whensaid second section of said test package is held by said transportassembly; a test package assembly mechanism for effecting securement ofsaid first and second sections of said test package in said mutualcooperation; a first imaging assembly operable to provide a die imageoutput signal; a second imaging assembly operable to provide a firsttest package section image output signal; and a controller assemblyoperable in response to a program stored in machine-readable memory,said controller assembly operably coupled to receive said die imageoutput signal and said first test package section image output signaland to control a position of said transport assembly at least partiallyin response thereto to position said die and said second section of saidtest package in relationship to said first section of said test packageand to cause said test package assembly mechanism to effect saidsecurement of said first and second sections of said test package insaid mutual cooperation with said die aligned with said first testpackage section.
 3. The apparatus of claim 2, wherein said transportassembly further includes a vacuum lift element for holding said secondtest package section.
 4. The apparatus of claim 3, wherein said testpackage assembly mechanism further includes gripper arms for selectivelymanipulating one test package section into said securement in saidmutual cooperation with another test package section.
 5. The apparatusof claim 4, wherein said gripper arms are adapted to selectivelymanipulate said one test package section to release said one testpackage section from said securement with respect to said another testpackage section.
 6. The apparatus of claim 1, further including:aconveyor assembly for providing groups of test package sections oncarriers to an assembly station; a die feed station; a lid feed station;said transport assembly vacuum lifting element being further configuredto lift a lid from said lid feed station to position said lid betweensaid die and said second section of said test package.
 7. The apparatusof claim 6, wherein said die feed station comprises a wafer feederstation.
 8. The apparatus of claim 6, wherein said die feed stationcomprises at least one die pack feeder.
 9. The apparatus of claim 6,wherein said die feed station comprises a wafer feeder station forpresenting a wafer from which a singulated die may be retrieved, andsaid apparatus further includes a third imaging assembly for locating aposition of a die on said wafer for retrieval.
 10. The apparatus ofclaim 6, wherein said first and second imaging assemblies each include arough camera for determining a general position of a die and a generalposition of a first test package section at said assembly station and afine camera for providing topographic characteristics of said die andsaid first test package section.
 11. The apparatus of claim 1, whereinsaid vacuum lifting element comprises a longitudinally-extending vacuumquill including a first central passage and a second, surroundingpassage, each of said passages terminating at a common exit planesubstantially transverse to the longitudinal extent of said vacuumquill.
 12. The apparatus of claim 11, further including a vacuum sourcein selective communication with said first and second passages.
 13. Theapparatus of claim 11, wherein said test package assembly mechanismfurther comprises first and second grippers laterally flanking saidvacuum quill and selectively movable toward and way from said vacuumquill.
 14. The apparatus of claim 11, further including at least onesuction aperture adjacent said vacuum quill above said exit plane and inselective communication with a vacuum source.
 15. The apparatus of claim14, wherein said first passage, said second passage and said at leastone suction aperture are in selective communication with separate vacuumsources.
 16. The apparatus of claim 14, wherein said first passage, saidsecond passage and said at least one suction aperture are in selectivecommunication with a common vacuum source.
 17. The apparatus of claim11, wherein said vacuum quill is vertically oriented and suspended fromsaid transport assembly on a vertically translatable linear slide. 18.The apparatus of claim 17, further including at least one test packagesection alignment element mounted to said linear slide laterallyadjacent said vacuum quill.
 19. The apparatus of claim 18, furtherincluding at least one suction aperture adjacent said vacuum quill abovesaid exit plane and in selective communication with a vacuum source. 20.The apparatus of claim 6, further including a die inverter.
 21. Theapparatus of claim 6, farther including a lid precisor.
 22. Theapparatus of claim 6, farther including a test package section feedstation separate from said conveyor assembly.
 23. The apparatus of claim6, wherein said conveyor assembly is further adapted to remove assembledtest packages on carriers from said assembly station.
 24. The apparatusof claim 2, farther including a conveyor assembly for transporting testpackage sections on carriers to an assembly station.
 25. The apparatusof claim 24, further including:a die feed station; a lid feed station;said transport assembly vacuum die lift element being further configuredto lift a lid from said lid feed station to position said lid betweensaid die and said second section of said test package.
 26. The apparatusof claim 25, wherein said die feed station comprises a wafer feederstation.
 27. The apparatus of claim 25, wherein said die feed stationcomprises at least one die pack feeder.
 28. The apparatus of claim 25,wherein said die feed station comprises a wafer feeder station forpresenting a wafer from which a singulated die may be retrieved, andsaid apparatus further includes a third imaging assembly for locating aposition of a die on said wafer for retrieval.
 29. The apparatus ofclaim 24, wherein said first and second imaging assemblies each includea rough camera for determining a general position of a die and a generalposition of a first test package section at said assembly station and afine camera for providing topographic characteristics of said die andsaid first test package section for said image output signals.
 30. Theapparatus of claim 2, wherein said die vacuum lift element comprises alongitudinally-extending vacuum quill including a first central passageand a second, surrounding passage, each of said passages terminating ata common exit plane substantially transverse to the longitudinal extentof said vacuum quill.
 31. The apparatus of claim 30, further including avacuum source in selective communication with said first and secondpassages.
 32. The apparatus of claim 30, wherein said test packageassembly mechanism further comprises first and second grippers laterallyflanking said vacuum quill and selectively movable toward and way fromsaid vacuum quill.
 33. The apparatus of claim 30, further including atleast one suction aperture adjacent said vacuum quill above said exitplane and in selective communication with a vacuum source.
 34. Theapparatus of claim 33, wherein said first passage, said second passageand said at least one suction aperture are in selective communicationwith separate vacuum sources.
 35. The apparatus of claim 33, whereinsaid first passage, said second passage and said at least one suctionaperture are in selective communication with a common vacuum source. 36.The apparatus of claim 30, wherein said vacuum quill is verticallyoriented and suspended from said transport assembly on a verticallytranslatable linear slide.
 37. The apparatus of claim 36, furtherincluding at least one test package section alignment element mounted tosaid linear slide.
 38. The apparatus of claim 37, further including atleast one suction aperture adjacent said vacuum quill above said exitplane and in selective communication with a vacuum source.
 39. Theapparatus of claim 25, further including a die inverter.
 40. Theapparatus of claim 25, further including a lid precisor.
 41. Theapparatus of claim 24, further including a test package section feedstation separate from said conveyor assembly.
 42. The apparatus of claim24, wherein said conveyor assembly is adapted to remove assembled testpackages on carriers from said assembly station.